Primary care physician
A primary care physician is a physician who provides both the first contact for a person with an undiagnosed health concern as well as continuing care of varied medical conditions, not limited by cause, organ system, or diagnosis. The term is used in the United States. In the past in the US and still in the United Kingdom, the equivalent term was/is general practitioner. All physicians first complete medical school. To become primary care physicians, medical school graduates undertake postgraduate training in primary care programs, such as family medicine, pediatrics or internal medicine; some HMOs consider gynecologists as PCPs for the care of women and have allowed certain subspecialists to assume PCP responsibilities for selected patient types, such as allergists caring for people with asthma and nephrologists acting as PCPs for patients on kidney dialysis. Emergency physicians are sometimes counted as primary care physicians. Emergency physicians see many primary care cases, but in contrast to family physicians and internists, they are trained and organized to focus on episodic care, acute intervention and discharge or transfer or referral to definitive care, with less of a focus on chronic conditions and limited provision for continuing care.
A set of skills and scope of practice may define a primary care physician including basic diagnosis and treatment of common illnesses and medical conditions. Diagnostic techniques include interviewing the patient to collect information on the present symptoms, prior medical history and other health details, followed by a physical examination. Many PCPs are trained in basic medical testing, such as interpreting results of blood or other patient samples, electrocardiograms, or x-rays. More complex and time-intensive diagnostic procedures are obtained by referral to specialists, with special training with a technology or increased experience and patient volume that make a risky procedure safer for the patient. After collecting data, the PCP arrives at a differential diagnosis and, with the participation of the patient, formulates a plan including components of further testing, specialist referral, therapy, diet or life-style changes, patient education, follow up results of treatment. Primary care physicians counsel and educate patients on safe health behaviors, self-care skills and treatment options, provide screening tests and immunizations.
A recent United States survey, found that 45 percent of primary care doctors were contractually obligated to not inform patients when they moved on to another practice. This is a problem in rural areas, which may forbid doctors from setting up new or competing practices in areas where physicians are scarce. A primary care physician is the first medical practitioner contacted by a patient because of factors such as ease of communication, accessible location and issues of cost and managed care requirements. In many countries residents are registered as patients of a doctor and must contact that doctor for referral to any other, they act as "gatekeepers," who regulate access to more costly specialists. Ideally, the primary care physician acts on behalf of the patient to collaborate with referral specialists, coordinate the care given by varied organizations such as hospitals or rehabilitation clinics, act as a comprehensive repository for the patient's records, provide long-term management of chronic conditions.
Continuous care is important for patients with medical conditions that encompass multiple organ systems and require prolonged treatment and monitoring, such as diabetes and hypertension. Studies that compare the knowledge base and quality of care provided by generalists versus specialists find that the specialists are more knowledgeable and provide better care. However, the studies examine the quality of care in the domain of the specialists. In addition, they need to account for clustering of physicians. Studies of the quality of preventive health care find the opposite results: primary care physicians perform best. An analysis of elderly patients found that patients seeing generalists, as compared to patients seeing specialists, were more to receive influenza vaccination. In health promotion counseling, studies of self-reported behavior found that generalists were more than internal medicine specialists to counsel patients and to screen for breast cancer. Exceptions may be diseases that are so common that primary care physicians develop their own expertise.
A study of patients with acute low back pain found the primary care physicians provided equivalent quality of care but at lower costs than orthopedic specialists. Factors associated with quality of care by primary care physicians: The more experience the primary care physician has with a specific disease. Physician group affiliation with networks of multiple groups; the dissemination of information to generalists compared to specialists is complicated. Two studies found specialists were more to adopt COX-2 drugs before the drugs were recalled by the FDA. One of the studies went on to state "using COX-2s as a model for physician adoption of new therapeutic agents, specialists were more to use these new medications for patients to benefit but were significantly more to use them for patients without a clear indication". A separate study found that specialists were less discriminating in their choice of journal reading. In the United States, the number of medical students entering family practice training dropped by 50% between 1997 and 2005.
In 1998, half of internal medicine re
Bacteria are a type of biological cell. They constitute a large domain of prokaryotic microorganisms. A few micrometres in length, bacteria have a number of shapes, ranging from spheres to rods and spirals. Bacteria were among the first life forms to appear on Earth, are present in most of its habitats. Bacteria inhabit soil, acidic hot springs, radioactive waste, the deep portions of Earth's crust. Bacteria live in symbiotic and parasitic relationships with plants and animals. Most bacteria have not been characterised, only about half of the bacterial phyla have species that can be grown in the laboratory; the study of bacteria is known as a branch of microbiology. There are 40 million bacterial cells in a gram of soil and a million bacterial cells in a millilitre of fresh water. There are 5×1030 bacteria on Earth, forming a biomass which exceeds that of all plants and animals. Bacteria are vital in many stages of the nutrient cycle by recycling nutrients such as the fixation of nitrogen from the atmosphere.
The nutrient cycle includes the decomposition of dead bodies. In the biological communities surrounding hydrothermal vents and cold seeps, extremophile bacteria provide the nutrients needed to sustain life by converting dissolved compounds, such as hydrogen sulphide and methane, to energy. Data reported by researchers in October 2012 and published in March 2013 suggested that bacteria thrive in the Mariana Trench, with a depth of up to 11 kilometres, is the deepest known part of the oceans. Other researchers reported related studies that microbes thrive inside rocks up to 580 metres below the sea floor under 2.6 kilometres of ocean off the coast of the northwestern United States. According to one of the researchers, "You can find microbes everywhere—they're adaptable to conditions, survive wherever they are."The famous notion that bacterial cells in the human body outnumber human cells by a factor of 10:1 has been debunked. There are 39 trillion bacterial cells in the human microbiota as personified by a "reference" 70 kg male 170 cm tall, whereas there are 30 trillion human cells in the body.
This means that although they do have the upper hand in actual numbers, it is only by 30%, not 900%. The largest number exist in the gut flora, a large number on the skin; the vast majority of the bacteria in the body are rendered harmless by the protective effects of the immune system, though many are beneficial in the gut flora. However several species of bacteria are pathogenic and cause infectious diseases, including cholera, anthrax and bubonic plague; the most common fatal bacterial diseases are respiratory infections, with tuberculosis alone killing about 2 million people per year in sub-Saharan Africa. In developed countries, antibiotics are used to treat bacterial infections and are used in farming, making antibiotic resistance a growing problem. In industry, bacteria are important in sewage treatment and the breakdown of oil spills, the production of cheese and yogurt through fermentation, the recovery of gold, palladium and other metals in the mining sector, as well as in biotechnology, the manufacture of antibiotics and other chemicals.
Once regarded as plants constituting the class Schizomycetes, bacteria are now classified as prokaryotes. Unlike cells of animals and other eukaryotes, bacterial cells do not contain a nucleus and harbour membrane-bound organelles. Although the term bacteria traditionally included all prokaryotes, the scientific classification changed after the discovery in the 1990s that prokaryotes consist of two different groups of organisms that evolved from an ancient common ancestor; these evolutionary domains are called Archaea. The word bacteria is the plural of the New Latin bacterium, the latinisation of the Greek βακτήριον, the diminutive of βακτηρία, meaning "staff, cane", because the first ones to be discovered were rod-shaped; the ancestors of modern bacteria were unicellular microorganisms that were the first forms of life to appear on Earth, about 4 billion years ago. For about 3 billion years, most organisms were microscopic, bacteria and archaea were the dominant forms of life. Although bacterial fossils exist, such as stromatolites, their lack of distinctive morphology prevents them from being used to examine the history of bacterial evolution, or to date the time of origin of a particular bacterial species.
However, gene sequences can be used to reconstruct the bacterial phylogeny, these studies indicate that bacteria diverged first from the archaeal/eukaryotic lineage. The most recent common ancestor of bacteria and archaea was a hyperthermophile that lived about 2.5 billion–3.2 billion years ago. Bacteria were involved in the second great evolutionary divergence, that of the archaea and eukaryotes. Here, eukaryotes resulted from the entering of ancient bacteria into endosymbiotic associations with the ancestors of eukaryotic cells, which were themselves related to the Archaea; this involved the engulfment by proto-eukaryotic cells of alphaproteobacterial symbionts to form either mitochondria or hydrogenosomes, which are still found in all known Eukarya. Some eukaryotes that contained mitochondria engulfed cyanobacteria-like organisms, leading to the formation of chloroplasts in algae and plants; this is known as primary endosymbiosis. Bacteria display a wide diversity of sizes, called morphologies.
Bacterial cells are about one-tenth the size of eukaryotic cells
White blood cell
White blood cells are the cells of the immune system that are involved in protecting the body against both infectious disease and foreign invaders. All white blood cells are produced and derived from multipotent cells in the bone marrow known as hematopoietic stem cells. Leukocytes are found throughout the body, including lymphatic system. All white blood cells have nuclei, which distinguishes them from the other blood cells, the anucleated red blood cells and platelets. Types of white blood cells can be classified in standard ways. Two pairs of broadest categories classify them either by cell lineage; these broadest categories can be further divided into the five main types: neutrophils, basophils and monocytes. These types are distinguished by their physical and functional characteristics. Monocytes and neutrophils are phagocytic. Further subtypes can be classified; the number of leukocytes in the blood is an indicator of disease, thus the white blood cell count is an important subset of the complete blood count.
The normal white cell count is between 4 × 109/L and 1.1 × 1010/L. In the US, this is expressed as 4,000 to 11,000 white blood cells per microliter of blood. White blood cells make up 1% of the total blood volume in a healthy adult, making them less numerous than the red blood cells at 40% to 45%. However, this 1 % of the blood makes a large difference to health. An increase in the number of leukocytes over the upper limits is called leukocytosis, it is normal. It is abnormal, when it is neoplastic or autoimmune in origin. A decrease below the lower limit is called leukopenia; this indicates a weakened immune system. The name "white blood cell" derives from the physical appearance of a blood sample after centrifugation. White cells are found in the buffy coat, a thin white layer of nucleated cells between the sedimented red blood cells and the blood plasma; the scientific term leukocyte directly reflects its description. It is derived from the Greek roots leuk- meaning "white" and cyt- meaning "cell".
The buffy coat may sometimes be green if there are large amounts of neutrophils in the sample, due to the heme-containing enzyme myeloperoxidase that they produce. All white blood cells are nucleated, which distinguishes them from the anucleated red blood cells and platelets. Types of leukocytes can be classified in standard ways. Two pairs of broadest categories classify them either by cell lineage; these broadest categories can be further divided into the five main types: neutrophils, basophils and monocytes. These types are distinguished by their physical and functional characteristics. Monocytes and neutrophils are phagocytic. Further subtypes can be classified. Granulocytes are distinguished from agranulocytes by their nucleus shape and by their cytoplasm granules; the other dichotomy is by lineage: Myeloid cells are distinguished from lymphoid cells by hematopoietic lineage. Lymphocytes can be further classified as T cells, B cells, natural killer cells. Neutrophils are the most abundant white blood cell, constituting 60-70% of the circulating leukocytes, including two functionally unequal subpopulations: neutrophil-killers and neutrophil-cagers.
They defend against fungal infection. They are first responders to microbial infection, they are referred to as polymorphonuclear leukocytes, although, in the technical sense, PMN refers to all granulocytes. They have a multi-lobed nucleus; this gives the neutrophils the appearance of having multiple nuclei, hence the name polymorphonuclear leukocyte. The cytoplasm may look transparent because of fine granules. Neutrophils are active in phagocytosing bacteria and are present in large amount in the pus of wounds; these cells are not able to die after having phagocytosed a few pathogens. Neutrophils are the most common cell type seen in the early stages of acute inflammation; the life span of a circulating human neutrophil is about 5.4 days. Eosinophils compose about 2-4% of the WBC total; this count fluctuates throughout the day and during menstruation. It rises in response to allergies, parasitic infections, collagen diseases, disease of the spleen and central nervous system, they are rare in the blood, but numerous in the mucous membranes of the respiratory and lower urinary tracts.
They deal with parasitic infections. Eosinophils are the predominant inflammatory cells in allergic reactions; the most important causes of eosinophilia include allergies such as asthma, hay fever, hives. They secrete chemicals that destroy these large parasites, such as hook worms and tapeworms, that are too big for any one WBC to phagocytize. In general, their nucleus is bi-lobed; the lobes are connected by a thin strand. The cytoplasm is full of granules that assume a characteristic pink-orange color with eosin stain
A microbiological culture, or microbial culture, is a method of multiplying microbial organisms by letting them reproduce in predetermined culture medium under controlled laboratory conditions. Microbial cultures are foundational and basic diagnostic methods used extensively as a research tool in molecular biology. Microbial cultures are used to determine the type of organism, its abundance in the sample being tested, or both, it is one of the primary diagnostic methods of microbiology and used as a tool to determine the cause of infectious disease by letting the agent multiply in a predetermined medium. For example, a throat culture is taken by scraping the lining of tissue in the back of the throat and blotting the sample into a medium to be able to screen for harmful microorganisms, such as Streptococcus pyogenes, the causative agent of strep throat. Furthermore, the term culture is more used informally to refer to "selectively growing" a specific kind of microorganism in the lab, it is essential to isolate a pure culture of microorganisms.
A pure culture is a population of cells or multicellular organisms growing in the absence of other species or types. A pure culture may originate from a single cell or single organism, in which case the cells are genetic clones of one another. For the purpose of gelling the microbial culture, the medium of agarose gel is used. Agar is a gelatinous substance derived from seaweed. A cheap substitute for agar is guar gum, which can be used for the isolation and maintenance of thermophiles. There are several types of bacterial culture methods that are selected based on the agent being cultured and the downstream use. One method of bacterial culture is liquid culture, in which the desired bacteria are suspended in a liquid nutrient medium, such as Luria Broth, in an upright flask; this allows a scientist to grow up large amounts of bacteria for a variety of downstream applications. Liquid cultures are ideal for preparation of an antimicrobial assay in which the experimenter inoculates liquid broth with bacteria and lets it grow overnight.
They would take aliquots of the sample to test for the antimicrobial activity of a specific drug or protein. As an alternative, the microbiologist may decide to use static liquid cultures; these cultures are not shaken and they provide the microbes with an oxygen gradient. Microbiological cultures can be grown in petri dishes of differing sizes that have a thin layer of agar-based growth medium. Once the growth medium in the petri dish is inoculated with the desired bacteria, the plates are incubated at the optimal temperature for the growing of the selected bacteria. After the desired level of growth is achieved, agar plates can be stored upside down in a refrigerator for an extended period of time to keep bacteria for future experiments. There are a variety of additives that can be added to agar before it is poured into a plate and allowed to solidify; some types of bacteria can only grow in the presence of certain additives. This can be used when creating engineered strains of bacteria that contain an antibiotic-resistance gene.
When the selected antibiotic is added to the agar, only bacterial cells containing the gene insert conferring resistance will be able to grow. This allows the researcher to select only the colonies that were transformed. Stab cultures are formed by solid agar in a test tube. Bacteria is introduced via an inoculation needle or a pipette tip being stabbed into the center of the agar. Bacteria grow in the punctured area. Stab cultures are most used for short-term storage or shipment of cultures. Microbial culture collections focus on the acquisition, production, preservation and distribution of viable cultures of standard reference microorganisms, cell lines and other materials for research in microbial systematics. Culture collection are repositories of type strains. Virus or phage cultures require host cells in which the phage multiply. For bacteriophages, cultures are grown by infecting bacterial cells; the phage can be isolated from the resulting plaques in a lawn of bacteria on a plate. Virus cultures are obtained from their appropriate eukaryotic host cells.
For single-celled eukaryotes, such as yeast, the isolation of pure cultures uses the same techniques as for bacterial cultures. Pure cultures of multicellular organisms are more isolated by picking out a single individual to initiate a culture; this is a useful technique for pure culture of fungi, multicellular algae, small metazoa, for example. Developing pure culture techniques is crucial to the observation of the specimen in question; the most common method to isolate individual cells and produce a pure culture is to prepare a streak plate. The streak plate method is a way to physically separate the microbial population, is done by spreading the inoculate back and forth with an inoculating loop over the solid agar plate. Upon incubation, colonies will arise and single cells will have been isolated from the biomass. Blood culture International Collection of Microorganisms from Plants Microbial dark matter Microbial Food Cultures NCPPB Screening cultures Sputum culture Synchronous culture EFFCA - European Food and Feed Cultutes Association.
Information about production and uses of microbial cultures as well as legislative aspects
Histology microanatomy, is the branch of biology which studies the tissues of animals and plants using microscopy. It is studied using a light microscope or electron microscope, the specimen having been sectioned and mounted on a microscope slide. Histological studies may be conducted using tissue culture, where live animal cells are isolated and maintained in an artificial environment for various research projects; the ability to visualize or differentially identify microscopic structures is enhanced through the use of staining. Histology is one of the major preclinical subjects in medical school. Medical students are expected to be familiar with the morphological features and function of all cells and tissues of the human body from an early stage of their studies, so histology stretches over several semesters. Histopathology, the microscopic study of diseased tissue, is an important tool in anatomical pathology, since accurate diagnosis of cancer and other diseases requires histopathological examination of samples.
Trained physicians licensed pathologists, are the personnel who perform histopathological examination and provide diagnostic information based on their observations. The trained personnel who prepare histological specimens for examination are histotechnicians, histotechnologists, histology technicians, histology technologists, medical scientists, medical laboratory technicians, or biomedical scientists, their support workers, their field of study is called histotechnology. In the 17th century, Italian Marcello Malpighi invented one of the first microscopes for studying tiny biological entities. Malpighi analysed several parts of the organs of bats and other animals under the microscope. Malpighi, while studying the structure of the lung, noticed its membranous alveoli and the hair-like connections between veins and arteries, which he named capillaries, his discovery established how the oxygen enters the blood stream and serves the body. In the 19th century, histology was an academic discipline in its own right.
The French anatomist Bichat introduced the concept of tissue in anatomy in 1801, the term "histology" first appeared in a book of Karl Meyer in 1819. Bichat described twenty-one human tissues, which can be subsumed under the four categories accepted by histologists; the usage of illustrations in histology, deemed as useless by Bichat, was promoted by Jean Cruveilhier. During the 19th century, many fixation techniques were developed by Adolph Hannover, Franz Schulze and Max Schultze, Alexander Butlerov and Benedikt Stilling. In the early 1830, Purkynĕ invented a microtome with high precision. Mounting techniques were developed by Rudolf Heidenhain, Salomon Stricker, Andrew Pritchard and Edwin Klebs. Koelliker's laboratory developed haematoxylin staining, in 1870s, Vysockij introduced eosin as a double or counter staining; the 1906 Nobel Prize in Physiology or Medicine was awarded to histologists Camillo Golgi and Santiago Ramon y Cajal. They had conflicting interpretations of the neural structure of the brain based on differing interpretations of the same images.
Cajal won the prize for his correct theory, Golgi for the silver staining technique he invented to make it possible. There are four basic types of animal tissues: muscle tissue, nervous tissue, connective tissue, epithelial tissue. All tissue types are subtypes of these four basic tissue types. Epithelium: the lining of glands, bowel and some organs like the liver and kidney Endothelium: the lining of blood and lymphatic vessels Mesothelium: the lining of pleural and pericardial spaces Mesenchyme: the cells filling the spaces between the organs, including fat, bone and tendon cells Blood cells: the red and white blood cells, including those found in lymph nodes and spleen Neurons: any of the conducting cells of the nervous system Germ cells: reproductive cells Placenta: an organ characteristic of true mammals during pregnancy, joining mother and offspring, providing endocrine secretion and selective exchange of soluble, but not particulate, blood-borne substances through an apposition of uterine and trophoblastic vascularised parts Stem cells: cells with the ability to develop into different cell typesThe tissues from plants and microorganisms can be examined histologically.
Their structure is different from animal tissues. For plants, the study of their tissues is more called as plant anatomy, with the following main types: Dermal tissue Vascular tissue Ground tissue Meristematic tissue Chemical fixatives are used to preserve tissue from degradation, to maintain the structure of the cell and of sub-cellular components such as cell organelles; the most common fixative for light microscopy is 10% neutral buffered formalin. For electron microscopy, the most used fixative is glutaraldehyde as a 2.5% solution in phosphate buffered saline. These fixatives preserve tissues or cells by irreversibly cross-linking proteins; the main action of these aldehyde fixatives is to cross-link amino groups in proteins through the formation of methylene bridges, in the case of formaldehyde, or by C5H10 cross-links in the case of glutaraldehyde. This process, while preserving the structural integrity of the cells and tissue can damage the biological functionality of proteins enzymes, and
The United States of America known as the United States or America, is a country composed of 50 states, a federal district, five major self-governing territories, various possessions. At 3.8 million square miles, the United States is the world's third or fourth largest country by total area and is smaller than the entire continent of Europe's 3.9 million square miles. With a population of over 327 million people, the U. S. is the third most populous country. The capital is Washington, D. C. and the largest city by population is New York City. Forty-eight states and the capital's federal district are contiguous in North America between Canada and Mexico; the State of Alaska is in the northwest corner of North America, bordered by Canada to the east and across the Bering Strait from Russia to the west. The State of Hawaii is an archipelago in the mid-Pacific Ocean; the U. S. territories are scattered about the Pacific Ocean and the Caribbean Sea, stretching across nine official time zones. The diverse geography and wildlife of the United States make it one of the world's 17 megadiverse countries.
Paleo-Indians migrated from Siberia to the North American mainland at least 12,000 years ago. European colonization began in the 16th century; the United States emerged from the thirteen British colonies established along the East Coast. Numerous disputes between Great Britain and the colonies following the French and Indian War led to the American Revolution, which began in 1775, the subsequent Declaration of Independence in 1776; the war ended in 1783 with the United States becoming the first country to gain independence from a European power. The current constitution was adopted in 1788, with the first ten amendments, collectively named the Bill of Rights, being ratified in 1791 to guarantee many fundamental civil liberties; the United States embarked on a vigorous expansion across North America throughout the 19th century, acquiring new territories, displacing Native American tribes, admitting new states until it spanned the continent by 1848. During the second half of the 19th century, the Civil War led to the abolition of slavery.
By the end of the century, the United States had extended into the Pacific Ocean, its economy, driven in large part by the Industrial Revolution, began to soar. The Spanish–American War and World War I confirmed the country's status as a global military power; the United States emerged from World War II as a global superpower, the first country to develop nuclear weapons, the only country to use them in warfare, a permanent member of the United Nations Security Council. Sweeping civil rights legislation, notably the Civil Rights Act of 1964, the Voting Rights Act of 1965 and the Fair Housing Act of 1968, outlawed discrimination based on race or color. During the Cold War, the United States and the Soviet Union competed in the Space Race, culminating with the 1969 U. S. Moon landing; the end of the Cold War and the collapse of the Soviet Union in 1991 left the United States as the world's sole superpower. The United States is the world's oldest surviving federation, it is a representative democracy.
The United States is a founding member of the United Nations, World Bank, International Monetary Fund, Organization of American States, other international organizations. The United States is a developed country, with the world's largest economy by nominal GDP and second-largest economy by PPP, accounting for a quarter of global GDP; the U. S. economy is post-industrial, characterized by the dominance of services and knowledge-based activities, although the manufacturing sector remains the second-largest in the world. The United States is the world's largest importer and the second largest exporter of goods, by value. Although its population is only 4.3% of the world total, the U. S. holds 31% of the total wealth in the world, the largest share of global wealth concentrated in a single country. Despite wide income and wealth disparities, the United States continues to rank high in measures of socioeconomic performance, including average wage, human development, per capita GDP, worker productivity.
The United States is the foremost military power in the world, making up a third of global military spending, is a leading political and scientific force internationally. In 1507, the German cartographer Martin Waldseemüller produced a world map on which he named the lands of the Western Hemisphere America in honor of the Italian explorer and cartographer Amerigo Vespucci; the first documentary evidence of the phrase "United States of America" is from a letter dated January 2, 1776, written by Stephen Moylan, Esq. to George Washington's aide-de-camp and Muster-Master General of the Continental Army, Lt. Col. Joseph Reed. Moylan expressed his wish to go "with full and ample powers from the United States of America to Spain" to seek assistance in the revolutionary war effort; the first known publication of the phrase "United States of America" was in an anonymous essay in The Virginia Gazette newspaper in Williamsburg, Virginia, on April 6, 1776. The second draft of the Articles of Confederation, prepared by John Dickinson and completed by June 17, 1776, at the latest, declared "The name of this Confederation shall be the'United States of America'".
The final version of the Articles sent to the states for ratification in late 1777 contains the sentence "The Stile of this Confederacy shall be'The United States of America'". In June 1776, Thomas Jefferson wrote the phrase "UNITED STATES OF AMERICA" in all capitalized letters in the headline of his "original Rough draught" of the Declaration of Independence; this draft of the document did not surface unti
A micrograph or photomicrograph is a photograph or digital image taken through a microscope or similar device to show a magnified image of an object. This is opposed to a macrograph or photomacrograph, an image, taken on a microscope but is only magnified less than 10 times. Micrography is the art of using microscopes to make photographs. A micrograph contains extensive details of microstructure. A wealth of information can be obtained from a simple micrograph like behavior of the material under different conditions, the phases found in the system, failure analysis, grain size estimation, elemental analysis and so on. Micrographs are used in all fields of microscopy. A light micrograph or photomicrograph is a micrograph prepared using an optical microscope, a process referred to as photomicroscopy. At a basic level, photomicroscopy may be performed by connecting a camera to a microscope, thereby enabling the user to take photographs at reasonably high magnification. Scientific use began in England in 1850 by Prof Richard Hill Norris FRSE for his studies of blood cells.
Roman Vishniac was a pioneer in the field of photomicroscopy, specializing in the photography of living creatures in full motion. He made major developments in light-interruption photography and color photomicroscopy. Photomicrographs may be obtained using a USB microscope attached directly to a home computer or laptop. An electron micrograph is a micrograph prepared using an electron microscope. Micrographs have micron bars, or magnification ratios, or both. Magnification is a ratio between the size of an object on its real size. Magnification can be a misleading parameter as it depends on the final size of a printed picture and therefore varies with picture size. A scale bar, or micron bar, is a line of known length displayed on a picture; the bar can be used for measurements on a picture. When the picture is resized the bar is resized making it possible to recalculate the magnification. Ideally, all pictures destined for publication/presentation should be supplied with a scale bar. All but one of the micrographs presented on this page do not have a micron bar.
The microscope has been used for scientific discovery. It has been linked to the arts since its invention in the 17th century. Early adopters of the microscope, such as Robert Hooke and Antonie van Leeuwenhoek, were excellent illustrators. After the invention of photography in the 1820s the microscope was combined with the camera to take pictures instead of relying on an artistic rendering. Since the early 1970s individuals have been using the microscope as an artistic instrument. Websites and traveling art exhibits such as the Nikon Small World and Olympus Bioscapes have featured a range of images for the sole purpose of artistic enjoyment; some collaborative groups, such as the Paper Project have incorporated microscopic imagery into tactile art pieces as well as 3D immersive rooms and dance performances. Close-up Digital microscope Macro photography Microphotograph Microscopy USB microscope Make a Micrograph – This presentation by the research department of Children's Hospital Boston shows how researchers create a three-color micrograph.
Shots with a Microscope – a basic, comprehensive guide to photomicrography Scientific photomicrographs – free scientific quality photomicrographs by Doc. RNDr. Josef Reischig, CSc. Micrographs of 18 natural fibres by the International Year of Natural Fibres 2009 Seeing Beyond the Human Eye Video produced by Off Book - Solomon C. Fuller bio Charles Krebs Microscopic Images Dennis Kunkel Microscopy Andrew Paul Leonard, APL Microscopic Cell Centered Database - Montage Nikon Small World Olympus Bioscapes Other examples